Question: what is petri dishes on agar jelly ?

Katie Fala answered on 12 Nov 2019:

Thanks for your question zest42cup! Petri dish normally refers to the glass/plastic container, which contains the agar jelly inside. The agar jelly provides a surface and nutrients of bacteria to grow, while the petri dish container keeps it closed so other bacteria from dust/air contaminating the plate. We use petri dishes with agar to grow bacteria and test new drugs like antibiotics for example to see how they affect the bacterial growth. On a side note, there are also lots of people who do AgarArt or Microbe Art by ‘painting’ bacterial cultures onto the agar plate: you can see a cute example by some of my talented labmates here: